JP7723232B2 - Support structure for sliding member - Google Patents

Description

The present invention relates to a support structure for a sliding member, and more specifically to a support structure for a sliding member in which the thrust load of the sliding member is received by the receiving surface of a receiving member.

A commonly known conventional spring support structure is one in which the thrust load of a coil spring is received by the receiving surface of a receiving member (see, for example, Patent Document 1). Patent Document 1 discloses a support structure in which a thrust bearing is interposed between the end of the coil spring and the receiving member (upper case). In this support structure, the thrust bearing effectively reduces the sliding resistance of the receiving surface of the receiving member caused by the up and down movement of the coil spring.

However, the spring support structure in Patent Document 1 uses a thrust bearing, which means that water and dust must not get inside the case. Furthermore, contact between dissimilar metals makes it prone to loose rust, making it less weather-resistant. It also requires periodic overhauls, making it less maintainable. Furthermore, the need for a thrust bearing and a case specifically for the thrust bearing increases production costs.

To solve the above-mentioned problems, a technology has been proposed in which a resin sheet or metal plate is interposed between the end of the coil spring and the receiving member. However, this proposed technology does not sufficiently reduce the sliding resistance of the receiving surface of the receiving member compared to thrust bearings. Furthermore, if a Duracon sheet, for example, is used as the resin sheet, it has high water resistance, but the infiltration of sand and dust can increase the coefficient of friction, making it impossible to improve weather resistance. Furthermore, if a stainless steel plate, for example, is used as the metal plate, contact between the stainless steel plate and the dissimilar metal is likely to cause loose rust, and the infiltration of sand and dust can significantly increase the coefficient of friction, making it impossible to improve weather resistance.

The above-mentioned problem also occurs in support structures other than spring support structures, in which thrust loads from rotating bodies, etc. are received by the receiving surface of a receiving member.

JP 2018-40490 A

The present invention was made in consideration of the above-mentioned current situation, and aims to provide a support structure for a sliding member that can sufficiently reduce the sliding resistance of the receiving surface of the receiving member and improve weather resistance.

The inventors discovered that combining thrust sheets made of resin materials with excellent self-lubricating properties and the same physical properties does not sufficiently reduce the sliding resistance of the receiving surface. However, they discovered that combining a first thrust sheet made of polyacetal resin, which has excellent self-lubricating properties, with a second thrust sheet made of fluororesin, which has excellent self-lubricating properties and a lower hardness and coefficient of friction than polyacetal resin, can sufficiently reduce the sliding resistance of the receiving surface, leading to the completion of the present invention.

In order to solve the above problems, the invention described in claim 1 is a support structure for a sliding member that receives the thrust load of the sliding member on a receiving surface of a receiving member, wherein an annular first thrust sheet that contacts the sliding member and an annular second thrust sheet that contacts the receiving surface are interposed between the sliding member and the receiving member, the first thrust sheet being made of polyacetal resin, and the second thrust sheet being made of fluororesin.
The invention described in claim 2 is the invention described in claim 1, wherein the first thrust sheet and the second thrust sheet are in contact with each other.
The invention described in claim 3 is the invention described in claim 1 or 2, wherein the sliding member is a coil spring or an elastic member arranged in contact with the axial end of the coil spring.
The invention as set forth in claim 4 is the invention as set forth in claim 1 or 2, wherein the sliding member is a rotating body rotatably supported by the receiving member.
The invention as set forth in claim 5 is the invention as set forth in claim 1 or 2, wherein the sliding member is a filler bolt that is screwed into the receiving member.
The invention as set forth in claim 6 is the invention as set forth in claim 1 or 2, wherein the sliding member is a connector that is connected to the tubular receiving member.
The invention described in claim 7 is the invention described in any one of claims 1 to 6, wherein a protrusion that can be inserted into the inside of the first thrust sheet and the second thrust sheet is formed on the receiving surface, and the inner diameter of the first thrust sheet is larger than the inner diameter of the second thrust sheet.
The invention as set forth in claim 8 is characterized in that the invention as set forth in any one of claims 1 to 3 is used in a suspension of a vehicle.

According to the support structure for a sliding member of the present invention, an annular first thrust sheet contacting the sliding member and an annular second thrust sheet contacting the receiving surface are interposed between the sliding member and the receiving member, the first thrust sheet being made of polyacetal resin, and the second thrust sheet being made of fluororesin. The combination of the first thrust sheet made of polyacetal resin, which has excellent self-lubricating properties, and the second thrust sheet made of fluororesin, which has excellent self-lubricating properties and a lower hardness and coefficient of friction than polyacetal resin, significantly reduces the sliding resistance of the receiving surface of the receiving member caused by the sliding member, thereby improving durability. Furthermore, the structure is highly water-resistant and resistant to the intrusion of sand and dust, thereby improving weather resistance. Furthermore, compared to conventional support structures equipped with thrust bearings, the structure offers superior maintainability and reduced production costs.
Furthermore, when the first thrust sheet and the second thrust sheet are in contact with each other, the sliding resistance of the receiving surfaces can be further reduced.
Furthermore, if the sliding member is a coil spring or an elastic member arranged in contact with the axial end of the coil spring, the sliding resistance of the receiving surface of the receiving member caused by the expansion and contraction of the coil spring can be sufficiently reduced.
Furthermore, when the sliding member is a rotating body that is rotatably supported by the receiving member, the sliding resistance of the rotating body on the receiving surface of the receiving member can be sufficiently reduced.
Furthermore, when the sliding member is a filler bolt that is screwed into the receiving member, the sliding resistance of the filler bolt on the receiving surface of the receiving member can be sufficiently reduced.
Furthermore, when the sliding member is a connector connected to the tubular receiving member, the sliding resistance of the receiving surface of the receiving member due to the connector can be sufficiently reduced.
Furthermore, if a convex portion is formed on the receiving surface and the inner diameter of the first thrust sheet is larger than that of the second thrust sheet, a gap is formed between the inner periphery of the relatively hard first thrust sheet and the convex portion of the receiving member, so that even if the sliding member vibrates, the first thrust sheet can rotate smoothly, reducing sliding resistance.
Furthermore, when used in a vehicle suspension, the running performance of the vehicle is improved.

The present invention will be further described in the following detailed description, which provides non-limiting examples of exemplary embodiments according to the present invention, and with reference to the mentioned drawings, in which like reference numerals refer to like parts throughout the several views of the drawings.
FIG. 2 is a cross-sectional view of the spring support structure according to the first embodiment. FIG. 2 is a perspective view of first and second thrust sheets according to the first embodiment. 1 is a table showing test results of Experimental Examples and Comparative Examples 1-5. 10A and 10B are explanatory diagrams for explaining a spring support structure according to a second embodiment. 10A and 10B are explanatory diagrams for explaining a support structure according to a third embodiment. 10A and 10B are explanatory diagrams for explaining a support structure according to a fourth embodiment. 10A and 10B are explanatory diagrams for explaining a support structure according to a fifth embodiment. 10A and 10B are explanatory diagrams for explaining another spring support structure.

The matters set forth herein are for illustrative purposes only and are intended to provide an illustrative description of embodiments of the present invention, with the objective of providing what is believed to be the most effective and readily understandable explanation of the principles and conceptual features of the present invention. In this regard, it is not intended to show structural details of the present invention beyond those necessary for a fundamental understanding of the present invention, and the description, taken in conjunction with the drawings, will make clear to those skilled in the art how some aspects of the present invention may be implemented in practice.

As shown in Figures 1 and 2, the support structure for a sliding member according to this embodiment is a support structure (1A-1F) for a sliding member in which the thrust load of the sliding member (3, 14, 18, 22, 25, 26) is received by the receiving surface (4a) of the receiving member (4A-4F). Between the sliding member (3, 14, 18, 22, 25, 26) and the receiving member (4A-4F) are interposed an annular first thrust sheet (11) that contacts the sliding member (3, 14, 18, 22, 25, 26) and an annular second thrust sheet (12) that contacts the receiving surface (4a). The first thrust sheet (11) is made of polyacetal resin, and the second thrust sheet (12) is made of fluororesin.

The support structures (1A to 1F) may be used for any purpose. For example, the support structures can be used in place of thrust bearings conventionally used in general equipment. The support structures are suitable for use as suspensions for vehicles such as automobiles, motorcycles, and bicycles. Examples of suspension types include MacPherson struts, double wishbones, multi-links, trailing arms, De Dion suspensions, torsion beams, and rigid suspensions. Furthermore, this support structure can improve suspension performance even in cases where the upper and lower surfaces of the coil springs cannot be installed parallel to each other, such as in pillow upper mounts where the coil springs are directly mounted, or torsion beam suspensions.
Furthermore, since the support structure does not require the application of any oils or fats such as grease, it is suitable for use in, for example, food manufacturing equipment, medical equipment, and equipment mounted in the aerospace industry.

There are no particular limitations on the type, size, material, etc. of the sliding members (3, 14, 18, 22, 25, 26). Examples of the sliding members include various springs (especially coil springs), rotating bodies, etc.
More specifically, the sliding member may be, for example, a coil spring (3) (see FIG. 1), or an elastic member (14) (see FIG. 4) disposed in contact with the axial end of the coil spring (3). A support structure for this type of sliding member (3, 14) is suitable for use, for example, as a suspension for a vehicle.
The sliding member may be, for example, a rotating body 18 rotatably supported on a receiving member 4C (see FIG. 5). This type of support structure for the sliding member 18 is suitable for use as a potter's wheel or a turntable.
The sliding member may be, for example, a filler bolt 22 that is screwed into a receiving member 4D (see FIG. 6). This type of support structure for the sliding member 22 is suitable for use as a reservoir for oil such as differential oil, engine oil, or transmission oil.
Furthermore, the sliding member may be, for example, a connector (25, 26) connected to a tubular receiving member (4E, 4F) (see FIG. 7). A support structure for this type of sliding member (25, 26) is suitable for use as, for example, a water faucet.

The type, size, material, etc. of the receiving members (4A-4F) are not particularly important. The receiving members (4A-4F) typically have a receiving surface (4a) that intersects (particularly perpendicular to) the direction in which the thrust load of the sliding members (3, 14, 18, 22, 25, 26) is applied. The receiving surface (4a) may have, for example, a raised protrusion (7) that can be inserted inside the first and second thrust sheets (11, 12) (see Figure 1).

There are no particular restrictions on the size, thickness, etc. of the first thrust sheet (11). The polyacetal resin constituting the first thrust sheet may be, for example, a polyacetal homopolymer such as polyoxymethylene (for example, "Delrin" manufactured by DuPont USA), or a polyacetal copolymer containing an oxymethylene structural unit and a comonomer structural unit (for example, "Duracon" manufactured by Polyplastics Co., Ltd.).
The first thrust sheet may include, for example, a lubricant and/or an additive (e.g., graphite fiber, glass fiber, metal fiber or powder, etc.).

The size, thickness, etc. of the second thrust sheet (12) are not particularly important. Examples of fluororesin that may be used to form the second thrust sheet include PTFE (polytetrafluoroethylene), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), PFA (perfluoroalkoxy fluororesin), and ETFE (ethylene-tetrafluoroethylene copolymer).

The inner diameters (id1, id2) of the first and second thrust sheets (11, 12) may be set to the same value, for example, but it is preferable that the inner diameter (id1) of the first thrust sheet (11) be set to a value larger than the inner diameter (id2) of the second thrust sheet (12). This is because a gap (S) is formed between the outer periphery of the protrusion (7) of the receiving member (4A to 4F) and the inner periphery of the first thrust sheet (11), thereby reducing sliding resistance even if the sliding member (3) vibrates (see FIG. 1).
The difference (id1-id2) between the inner diameter (id1) of the first thrust seat (11) and the inner diameter (id2) of the second thrust seat (12) is, for example, 0.1 to 3 mm (preferably 0.5 to 2 mm).

The outer diameters (od1, od2) of the first and second thrust sheets (11, 12) may be set to different values, for example. However, from the standpoint of ease of assembly of the first and second thrust sheets (11, 12), it is preferable that the outer diameters (od1, od2) of the first and second thrust sheets (11, 12) be set to approximately the same value.

For example, another thrust sheet may be interposed between the first and second thrust sheets (11, 12), but from the viewpoint of reducing the number of parts, it is preferable that the first and second thrust sheets (11, 12) are directly stacked on top of each other.
Other thrust sheets may include, for example, one or more thrust sheets made of polyacetal resin, one or more thrust sheets made of fluororesin, or a thrust sheet that combines both.
As a reference example, there is a configuration in which a first thrust sheet made of polyacetal resin, a second thrust sheet made of fluororesin, and a third thrust sheet made of polyacetal resin are laminated together, and there is also a configuration in which the first to third thrust sheets made of fluororesin are laminated together.

The polyacetal resin that makes up the first thrust sheet (11) has excellent fatigue resistance. It is also a well-balanced resin with excellent friction and wear resistance, low noise, chemical resistance, creep resistance, and dimensional stability. It has low water absorption. While it originally had poor weather resistance, grades with improved weather resistance have recently been developed through the use of UV stabilizers and pigments. It is also the most widely used material in general environmental temperature ranges (automobiles, office equipment, AV equipment, etc.). As an engineering plastic, it has well-balanced mechanical properties and is self-lubricating. It is also easy to mold, inexpensive, and has good dimensional accuracy. Furthermore, its sliding properties are significantly improved by the addition of lubricants, etc.

Polyacetal resin is known to have physical properties such as a specific gravity of 1.41 to 1.42 and a hardness (Rockwell) of M90/R120.
It is also known that its mechanical properties include, for example, a tensile yield stress of 61 to 69 MPa, a breaking strain of 20 to 75%, a tensile modulus of 2800 MPa, an Izod impact strength of 6.9 to 12.0 KJ/m ² , a compressive yield stress of 98 to 130 MPa, a bending stress of 88 to 96 MPa, and a tapered abrasion resistance of 6 to 20 mg/1000.
It is also known that its thermal properties include a heat resistance temperature (continuous) of 90 to 100°C, a deflection temperature under load (0.45/1.8 MPa) of 160 to 170°C/110 to 120°C, a brittle temperature of -40°C, a linear expansion coefficient of 8.1 to 8.5 × 10 ^-5 K ^-1 , a thermal conductivity of 0.25 W/m·k, and slow combustion resistance.
It is also known that its electrical properties include a volume resistivity of 10 ^15-17 Ω·cm, a withstand voltage of 26 to 34 MV/m, and a dielectric constant of 3.1 to 3.9×10 ⁶ Hz.
In terms of chemical properties, for example, acid resistance is rated as x on a 4-point scale, alkali resistance is rated as x on a 4-point scale, solvent resistance is rated as ⊚ on a 4-point scale, and water absorption is 0.22 to 0.25%.
Furthermore, it is known that its optical properties include, for example, a refractive index of 1.48, transparency of opaque, and weather resistance of slight discoloration.

The fluororesin that constitutes the second thrust sheet (12) has excellent heat resistance, cold resistance, chemical resistance, hot water resistance, and weather resistance, and also has excellent non-adhesiveness, low friction, and high frequency characteristics.
PTFE resin, in particular, is the most popular material among fluororesins and is widely used. It also has the lowest coefficient of friction among existing materials and excellent chemical resistance, making it suitable for a wide range of applications. Its own abrasion resistance and mechanical strength can be improved by adding fillers or by combining it with metal materials. The improvement is remarkable.

The physical properties of PTFE resin are known to be, for example, a specific gravity of 1.70 to 2.20 and a hardness (Rockwell) of R75 to R95.
It is also known that its mechanical properties include, for example, a tensile yield stress of 19 to 34 MPa, a breaking strain of 200 to 400%, a tensile modulus of 390 MPa, an Izod impact strength of 14 to 16 KJ/m ² , a compressive yield stress of 15 MPa, and a tapered abrasion resistance of 7 mg/1000.
It is also known that its thermal properties include a heat resistance temperature (continuous) of 290°C, a deflection temperature under load (0.45/1.8 MPa) of 121°C/90°C, a brittle temperature of <-100°C, a linear expansion coefficient of 4.5 to 7.0 x ^10-5 K ^-1 , a thermal conductivity of 0.12 to 0.25 W/m·k, and heat resistance that is non-flammable.
It is also known that its electrical properties include a volume resistivity of >10 ²⁰ Ω·cm, a withstand voltage of 19 MV/m, and a dielectric constant of <2.1×10 ⁶ Hz.
In terms of chemical properties, it is known that the acid resistance is rated as ⊚ on a scale of 4, the alkali resistance is rated as ⊚ on a scale of 4, the solvent resistance is rated as ⊚ on a scale of 4, and the water absorption is 0.00%.
Furthermore, it is known to have optical properties such as a refractive index of 1.35, opaque transparency, and excellent weather resistance.

It is also known that the static friction coefficient of polyacetal resin (homopolymer, natural/carbon glass filled) is 0.32 and the dynamic friction coefficient is 0.18, while the static friction coefficient of PTFE resin (natural) is 0.13 and the dynamic friction coefficient is 0.09.
Furthermore, it is known that when the specific wear rate of PTFE resin (natural) is 1.0, the specific wear rate of polyacetal resin (homopolymer, natural) is 2.4, and the specific wear rate of polyacetal resin (homopolymer, carbon glass filled) is 2.0.

In the present support structure for a sliding member (1A-1F), the first thrust sheet (11) in contact with the sliding members (3, 14, 18, 22, 25, 26) is made of polyacetal resin, which has excellent self-lubricating properties. The second thrust sheet (12) in contact with the receiving surface (4a) is made of fluororesin, which has excellent self-lubricating properties and a lower hardness and coefficient of friction than polyacetal resin. This synergistically combines the self-lubricating properties of the first and second thrust sheets (11, 12), and the second thrust sheet (12) is thought to act as a cushion for the first thrust sheet (11). As a result, the sliding resistance of the sliding members (3, 14, 18, 22, 25, 26) on the receiving surface (4a) of the receiving member (4A-4F) is sufficiently reduced. Furthermore, the structure is more resistant to sand and dust penetration, improving weather resistance.
In particular, when the first and thrust sheets (11, 12) are in contact with each other and overlapped, the cushioning function of the second thrust sheet (12) acts directly on the first thrust sheet (11), resulting in a significant reduction in sliding resistance and a significant effect in suppressing the intrusion of sand, dust, etc.
Furthermore, when the support structure (1A to 1F) of the present sliding member is used in a high-temperature environment, the second thrust sheet (12) with its excellent thermal properties effectively absorbs and dissipates heat, thereby covering up the thermal expansion of the first thrust sheet (11) and improving durability.

Note that the symbols in parentheses for each component described in the above embodiment indicate their correspondence with the specific components described in the examples below.

The present invention will be specifically explained below with reference to Examples 1 to 5 using the drawings. In Examples 1 and 2, a spring support structure used in an automobile suspension is exemplified as the "support structure for a sliding member" according to the present invention.

Example 1
1 and 2, the spring support structure 1A according to this embodiment is configured such that both axial ends of a coil spring 3 (exemplified as a "sliding member" according to the present invention) are supported by upper and lower receiving members 4A (spring seats). Between the axial end of this coil spring 3 and the receiving member 4A, there are disposed an annular first thrust sheet 11 in contact with the axial end face of the coil spring 3 and a second annular thrust sheet 12 in contact with the receiving surface 4a of the receiving member 4A in an overlapping state.

The coil spring 3 is made of metal (e.g., spring steel). The receiving member 4A is made of a different metal (e.g., aluminum) from the coil spring 3. The receiving member 4A has a receiving surface 4a that is perpendicular to the axial direction of the coil spring 3. A cylindrical protrusion 7 that can be inserted into the first and second thrust sheets 11 and 12 is raised on this receiving surface 4a. The receiving member 4A is also circular in plan view.

As shown by the phantom lines in Figure 1, a damper 8 is attached to the inside of the lower receiving member 4A. The piston rod 8a of the damper 8 is inserted into the central hole of the upper receiving member 4A. An upper mount 9, which is fixed to a component on the automobile, is attached to the tip of this piston rod 8a.

The first thrust sheet 11 is made of polyacetal resin (e.g., Duracon). This first thrust sheet 11 has an inner diameter id1 of approximately 65 mm, an outer diameter od1 of approximately 84 mm, and a thickness t1 of approximately 1 mm (see Figure 2).

The second thrust sheet 12 is made of a fluororesin (e.g., PTFE). This second thrust sheet 12 has an inner diameter id2 of approximately 64 mm, an outer diameter od2 of approximately 84 mm, and a thickness t2 of approximately 1 mm (see Figure 2).

The outer diameters od1 and od2 of the first and second thrust sheets 11 and 12 are set to approximately the same value. The inner diameter id1 of the first thrust sheet 11 is set to a value larger than the inner diameter id2 of the second thrust sheet 12. A gap S is formed between the outer periphery of the protrusion 7 of the receiving member 4A and the inner periphery of the first thrust sheet 11 (see Figure 1). On the other hand, no gap is formed between the outer periphery of the protrusion 7 of the receiving member 4A and the inner periphery of the second thrust sheet 12.

Next, the operation and effect of the spring support structure 1A configured as described above will be described.
In a suspension equipped with this spring support structure 1A, when twisting occurs due to expansion and contraction of the coil spring 3 while the vehicle is running, the sliding resistance of the receiving surface 4a of the receiving member 4A is effectively reduced by the first and second thrust sheets 11, 12 made of a resin material with excellent wear resistance.

In this spring support structure 1A, a first thrust sheet 11 (annular) contacting the axial end of the coil spring 3 and a second thrust sheet 12 (annular) contacting the receiving surface 4a are interposed between the coil spring 3 and the receiving member 4A. The first thrust sheet 11 is made of polyacetal resin, and the second thrust sheet 12 is made of fluororesin. This combination of the first thrust sheet 11 (made of polyacetal resin, which has excellent self-lubricating properties) and the second thrust sheet 12 (made of fluororesin, which has excellent self-lubricating properties and a lower hardness and coefficient of friction than polyacetal resin) significantly reduces the sliding resistance of the receiving surface 4a of the receiving member 4A due to the expansion and contraction of the coil spring 3, thereby enhancing durability. This results in excellent buckling prevention, consistently drawing out the inherent performance of the coil spring 3 and enabling smooth operation, resulting in a significantly improved ride comfort. Furthermore, the structure is highly water-resistant and resistant to the penetration of sand and dust, thereby enhancing weather resistance. Furthermore, compared to conventional support structures equipped with thrust bearings, this system offers superior maintainability and reduces production costs.

Furthermore, this spring support structure 1A is placed near the engine and can reach high temperatures of 60-70°C in the summer. However, the second thrust sheet 12, which has excellent thermal properties, effectively absorbs and dissipates heat, thereby covering up the thermal expansion of the first thrust sheet 11.

Furthermore, in this embodiment, a protrusion 7 is raised on the receiving surface 4a, and the inner diameter id1 of the first thrust sheet 11 is set to a value larger than the inner diameter id2 of the second thrust sheet 12. As a result, a gap S is formed between the inner periphery of the first thrust sheet 11 and the outer periphery of the protrusion 7 of the receiving member 4A. Therefore, even if the coil spring 3 vibrates, the first thrust sheet 11 rotates smoothly, reducing sliding resistance.

Furthermore, in this embodiment, the outer diameters od1 and od2 of the first and second thrust sheets 11 and 12 are set to approximately the same value. As a result, even if the above-mentioned gap S is formed, by aligning the outer peripheries of the first and second thrust sheets 11 and 12, the sheets 11 and 12 can be set in the correct assembly position.

Next, the test results of the spring support structures of the experimental example and comparative examples 1-5 will be described.
In this test, each spring support structure was installed in the suspension of a vehicle, and the sliding resistance and weather resistance of the receiving member were evaluated. These evaluations were based on observing the operation of the spring support structure and the riding comfort of the passengers while the vehicle was running.

In the experimental examples, one Duracon sheet and one PTFE sheet were interposed between the coil spring and the receiving member. In Comparative Example 1, one Duracon sheet was interposed between the coil spring and the receiving member. In Comparative Example 2, a metal thrust bearing was interposed between the coil spring and the receiving member. In Comparative Example 3, one nylon or Duracon resin sheet and one stainless steel plate were interposed between the coil spring and the receiving member. In Comparative Example 4, two PTFE sheets were interposed between the coil spring and the receiving member. In Comparative Example 5, two Duracon sheets were interposed between the coil spring and the receiving member.

As a result, it was confirmed that in the experimental example, the sliding resistance of the contact surface of the receiving member (spring mount) due to the up and down movement of the coil spring was significantly reduced, as shown in Figure 3. Furthermore, because the soft resin material with excellent abrasion resistance is combined with the hard resin material, it is highly water resistant and does not easily allow sand and dust to penetrate, and it was confirmed that it has high weather resistance.
Furthermore, according to the experience of a driver who participated in a gymkhana (a motor sport played on paved roads) in a car, it was confirmed that the spring support structure of this experimental example had extremely good durability compared to the spring support structure of Comparative Example 1.

The spring support structure in the experimental example can be attached to both ends of the coil spring. The recommended attachment positions are one end and both ends of the spring. Furthermore, in the experimental example, as part of maintenance, the Duracon sheet and PTFE sheet require replacement when worn out. Furthermore, the annular Duracon sheet and PTFE sheet can be obtained by cutting them out from the material.

In Comparative Example 1, it was confirmed that the sliding resistance of the contact surface of the receiving member (spring mount) due to the up and down movement of the coil spring was clearly reduced. Furthermore, because it is a single Duracon sheet, it has high water resistance, but the coefficient of friction tends to increase when sand and dust get in, and it was confirmed that its weather resistance is somewhat low.

The spring support structure of Comparative Example 1 can be attached to both ends of the coil spring. The recommended attachment position is preferably both ends of the spring. Furthermore, in Comparative Example 1, maintenance requires replacement of the Duracon sheet when it wears out. Furthermore, the annular Duracon sheet can be obtained by cutting it out from the material.

In Comparative Example 2, it was confirmed that the sliding resistance of the contact surface of the receiving member (spring mount) due to the up and down movement of the coil spring was significantly reduced. Furthermore, because a metal bearing is used, it is strictly prohibited for water or dust to enter the case, and it was confirmed that contact between dissimilar metals is prone to causing loose rust, resulting in poor weather resistance.

The spring support structure of Comparative Example 2 can only be attached to one end of the spring. Furthermore, Comparative Example 1 requires periodic overhaul work as part of maintenance. Furthermore, Comparative Example 2 requires the preparation of a thrust bearing and a case specifically for the thrust bearing.

In Comparative Example 3, it was confirmed that the sliding resistance of the contact surface of the receiving member (spring mount) due to the up and down movement of the coil spring was clearly reduced. It was also confirmed that contact between the stainless steel plate and dissimilar metals was likely to result in loose rust, and that the coefficient of friction tended to increase due to the intrusion of sand and dust, resulting in poor weather resistance.

The spring support structure of Comparative Example 3 can be attached to both ends of the coil spring. The recommended attachment position is preferably both ends of the spring. Furthermore, in Comparative Example 3, maintenance requires checking the condition of the stainless steel plate and greasing it. Furthermore, the annular resin sheet and stainless steel plate are obtained by cutting them out from the material.

In Comparative Example 4, because the material was soft resin, it was confirmed that smooth operation was difficult when the spring end was jammed.

In Comparative Example 5, because the material was a hard resin, friction tended to increase and it was confirmed that it was not suitable for multiple plates.

Example 2
Next, a spring support structure 1B according to a second embodiment will be described. The parts having substantially the same configuration as those in the spring support structure 1A according to the first embodiment will be designated by the same reference numerals and detailed description thereof will be omitted.

As shown in FIG. 4, the spring support structure 1B of this embodiment is configured such that a rubber elastic member 14 (exemplified as the "sliding member" according to the present invention) is placed in contact with the axial end of the coil spring 3 and is supported by a metal receiving member 4B (vehicle body-side receiving member 4B) on the vehicle body side. Between this elastic member 14 and receiving member 4B, there are disposed a first annular thrust sheet 11 in contact with the surface of the elastic member 14 and a second annular thrust sheet 12 in contact with the receiving surface 4a of the receiving member 4B, which are stacked one on top of the other. The first thrust sheet 11 is made of polyacetal resin (e.g., Duracon, etc.). The second thrust sheet 12 is made of fluororesin (e.g., PTFE, etc.).

This spring support structure 1B provides substantially the same effects as the spring support structure 1A of Example 1.

Example 3
Next, a support structure 1C according to Example 3 will be described, but parts having substantially the same configuration as those in the spring support structure 1A according to Example 1 will be assigned the same reference numerals and detailed description will be omitted. In Example 3, a support structure 1C for a rotating body used as a potter's wheel or a turntable will be exemplified as a "support structure for a sliding member" according to the present invention.

As shown in Figure 5, the rotor support structure 1C supports a rotor 18, including a rotor shaft 17, for rotation about an axis perpendicular to the receiving surface 4a of a receiving member 4C, and is configured so that the thrust load of the rotor 18 is received by the receiving surface 4a of the receiving member 4C. Between the end of the rotor 18 and the receiving member 4C, an annular first thrust sheet 11 contacting the rotor 18 and an annular second thrust sheet 12 contacting the receiving surface 4a of the receiving member 4C are stacked. The first thrust sheet 11 is made of polyacetal resin (e.g., Duracon), and the second thrust sheet 12 is made of fluororesin (e.g., PTFE).
The support structure 1C for the rotating body may be used in place of a metal bearing or in combination with a metal bearing.

This rotating body support structure 1C can sufficiently reduce the sliding resistance of the rotating body 18 on the receiving surface 4a of the receiving member 4C, thereby increasing durability. As a result, the rotating body 18 can rotate stably relative to the receiving member 4C for an extended period of time.

Example 4
Next, a support structure 1D according to Example 4 will be described, but parts having substantially the same configuration as those in the spring support structure 1A according to Example 1 will be assigned the same reference numerals and detailed description will be omitted. Note that in Example 4, a support structure 1D for a filler bolt used as an oil reservoir for differential oil or the like will be exemplified as a "support structure for a sliding member" according to the present invention.

As shown in Figure 6, this filler bolt support structure 1D is configured so that a filler bolt 22 is threaded into a threaded portion 23 formed on a receiving member 4D, and the thrust load of the filler bolt 22 is received by the receiving surface 4a of the receiving member 4D. Between the head 22a of the filler bolt 22 and the receiving member 4D, there are stacked and interposed an annular first thrust sheet 11 that contacts the head 22a of the filler bolt 22 and a second thrust sheet 12 that contacts the receiving surface 4a of the receiving member 4D. The first thrust sheet 11 is made of polyacetal resin (e.g., Duracon, etc.). The second thrust sheet 12 is made of fluororesin (e.g., PTFE, etc.).

This filler bolt support structure 1D can sufficiently reduce the sliding resistance of the filler bolt 22 on the receiving surface 4a of the receiving member 4D, thereby increasing durability. As a result, force is applied evenly from the filler bolt 22 to the receiving surface 4a, allowing the first and second thrust sheets 11, 12 to function effectively as gaskets.

Example 5
Next, support structures 1E and 1F according to Example 5 will be described, but parts having substantially the same configuration as those in the spring support structure 1A according to Example 1 will be assigned the same reference numerals and detailed description will be omitted. Note that in Example 5, support structures 1E and 1F for connectors used as water faucets will be exemplified as the "support structure for a sliding member" according to the present invention.

As shown in Figure 7, the support structure 1E for the connector is configured such that a nut body 25 (exemplified as the "connector" according to the present invention) is threaded onto a tubular receiving member 4E, and the thrust load of the nut body 25 is received by the receiving surface 4a (axial end surface) of the receiving member 4E. Between the nut body 25 and the receiving member 4E, an annular first thrust sheet 11 contacting the nut body 25 and an annular second thrust sheet 12 contacting the receiving surface 4a of the receiving member 4E are stacked. The first thrust sheet 11 is made of polyacetal resin (e.g., Duracon), and the second thrust sheet 12 is made of fluororesin (e.g., PTFE).
A faucet operating part 30 is provided penetrating the center of the nut body 25. This faucet operating part 30 includes a handle 31, a spindle 32 that moves along the axis of the receiving member 4E when the handle 31 is operated, and a packing block 33 that is provided at the tip of the spindle 32 and opens and closes a hole 34.

This connector support structure 1E can sufficiently reduce the sliding resistance of the nut body 25 on the receiving surface 4a of the receiving member 4E, thereby increasing durability. As a result, the first and second thrust sheets 11, 12 can effectively function as packing in the water faucet section.

The connector support structure 1F rotatably supports a faucet spout 26 (exemplified as a "connector" according to the present invention) on a tubular receiving member 4F, and is configured so that the thrust load of the faucet spout 26 is received by the receiving surface 4a (axial end surface) of the receiving member 4F. Between the faucet spout 26 and the receiving member 4F, there are interposed an annular first thrust sheet 11 that contacts the enlarged diameter portion 26a of the faucet spout 26 and an annular second thrust sheet 12 that contacts the receiving surface 4a of the receiving member 4F in a stacked state. The first thrust sheet 11 is made of polyacetal resin (e.g., Duracon). The second thrust sheet 12 is made of fluororesin (e.g., PTFE).
A nut body 35 is screwed onto the tip of the receiving member 4F.

This connection support structure 1F can sufficiently reduce the sliding resistance of the faucet spout 26 on the receiving surface 4a of the receiving member 4F, thereby increasing durability. As a result, the faucet spout 26 can rotate stably relative to the receiving member 4F over an extended period of time, and the first and second thrust sheets 11, 12 can function effectively as gaskets in the water faucet.

The present invention is not limited to the above-described Examples 1 to 5, and various modifications can be made within the scope of the present invention depending on the purpose and application. In other words, while Example 1 above illustrates a spring support structure 1A having two pairs of thrust sheets 11, 12 corresponding to both ends of the coil spring 3, the present invention is not limited to this. For example, the spring support structure 1A may also have one pair of thrust sheets 11, 12 corresponding to only one end of the coil spring 3.

Furthermore, for example, in a configuration in which multiple coil springs 3 are arranged in the axial direction as shown in Figure 8, two pairs of first and second thrust sheets 11, 12 may be provided on a receiving member 4 connecting the axial ends of both springs 3.

Furthermore, in the above-mentioned Example 1, a configuration in which a gap S is formed between the inner periphery of the first thrust sheet 11 and the outer periphery of the convex portion 7 of the receiving member 4A was exemplified, but this is not limited to this. For example, it is also possible not to form a gap S between the inner periphery of the first thrust sheet 11 and the outer periphery of the convex portion 7 of the receiving member 4A.

Furthermore, in the above-mentioned Example 1, a configuration was exemplified in which no gap S was formed between the inner periphery of the second thrust sheet 12 and the outer periphery of the convex portion 7 of the receiving member 4A, but this is not limited to this. For example, a gap S may be formed between the inner periphery of the second thrust sheet 12 and the outer periphery of the convex portion 7 of the receiving member 4A.

The present invention is not limited to the embodiments detailed above, and various modifications and variations are possible within the scope of the claims of the present invention.

This invention is widely used as a technology for supporting a sliding member with a receiving member.

1A-1F: Support structure, 3: Coil spring (sliding member), 4A-4F: Receiving member, 4a: Receiving surface, 11: First thrust sheet, 12: Second thrust sheet, 14: Elastic member (sliding member), 18: Rotating body (sliding member), 22: Filler bolt (sliding member), 25: Nut body (connecting body), 26: Faucet spout (connecting body), id1: Inner diameter of first thrust sheet, id2: Inner diameter of second thrust sheet.

Claims (4)

A support structure for a sliding member that receives a thrust load of the sliding member on a receiving surface of a receiving member,
a first thrust sheet having a uniform thickness and an annular shape that contacts the sliding member and a second thrust sheet having a uniform thickness and annular shape that contacts the receiving surface are interposed between the sliding member and the receiving member,
the first thrust sheet is made of polyacetal resin,
the second thrust sheet is formed of a fluororesin having a hardness and a coefficient of friction smaller than those of polyacetal resin so that the self-lubricating properties of the first thrust sheet and the second thrust sheet are synergistically combined and the second thrust sheet functions as a cushion for the first thrust sheet ;
a protrusion that can be inserted into the first thrust sheet and the second thrust sheet is formed on the receiving surface;
an inner diameter of the first thrust seat is larger than an inner diameter of the second thrust seat;
The outer diameter of the first thrust seat is the same as the outer diameter of the second thrust seat,
The outer diameter of the receiving surface is the same as the outer diameter of the second thrust seat,
the first thrust sheet and the second thrust sheet are in contact with each other,
the sliding member is a coil spring,
The receiving member includes an upper receiving member and a lower receiving member,
the first thrust sheet contacting an upper end of the coil spring and the second thrust sheet contacting the receiving surface of the upper receiving member are interposed between the coil spring and the upper receiving member,
the first thrust sheet contacting a lower end of the coil spring and the second thrust sheet contacting the receiving surface of the lower receiving member are interposed between the coil spring and the lower receiving member,
A support structure for a sliding member, characterized in that it is used in a vehicle suspension . A support structure for a sliding member that receives a thrust load of the sliding member on a receiving surface of a receiving member,
a first thrust sheet having a uniform thickness and an annular shape that contacts the sliding member and a second thrust sheet having a uniform thickness and annular shape that contacts the receiving surface are interposed between the sliding member and the receiving member,
the first thrust sheet is made of polyacetal resin,
the second thrust sheet is formed of a fluororesin having a hardness and a coefficient of friction smaller than those of polyacetal resin so that the self-lubricating properties of the first thrust sheet and the second thrust sheet are synergistically combined and the second thrust sheet functions as a cushion for the first thrust sheet ;
a protrusion that can be inserted into the first thrust sheet and the second thrust sheet is formed on the receiving surface;
an inner diameter of the first thrust seat is larger than an inner diameter of the second thrust seat;
The outer diameter of the first thrust seat is the same as the outer diameter of the second thrust seat,
The outer diameter of the receiving surface is the same as the outer diameter of the second thrust seat,
the first thrust sheet and the second thrust sheet are in contact with each other,
The sliding member has an upper coil spring and a lower coil spring,
the receiving member has an upper receiving surface that receives the upper coil spring and a lower receiving surface that receives the lower coil spring,
the first thrust sheet contacting a lower end of the upper coil spring and the second thrust sheet contacting the upper receiving surface are interposed between the upper coil spring and the upper receiving surface of the receiving member,
the first thrust sheet contacting an upper end of the lower coil spring and the second thrust sheet contacting the lower receiving surface are interposed between the lower coil spring and the lower receiving surface of the receiving member,
A support structure for a sliding member, characterized in that it is used in a vehicle suspension . A support structure for a sliding member that receives a thrust load of the sliding member on a receiving surface of a receiving member,
an annular first thrust sheet in contact with the sliding member and an annular second thrust sheet in contact with the receiving surface are interposed between the sliding member and the receiving member;
the first thrust sheet is made of polyacetal resin,
the second thrust sheet is made of fluororesin,
10. A support structure for a sliding member, wherein the sliding member is a filler bolt that is screwed into the receiving member. A support structure for a sliding member that receives a thrust load of the sliding member on a receiving surface of a receiving member,
an annular first thrust sheet in contact with the sliding member and an annular second thrust sheet in contact with the receiving surface are interposed between the sliding member and the receiving member;
the first thrust sheet is made of polyacetal resin,
the second thrust sheet is made of fluororesin,
The support structure for a sliding member, wherein the sliding member is a connector that is connected to the tubular receiving member.